Dorothea Andel

Awake nasotracheal fiberoptic intubation: patient comfort, intubating conditions, and hemodynamic stability during conscious sedation with remifentanil.

Awake nasotracheal fiberoptic intubation requires an anesthetic management that provides sufficient patient comfort, adequate intubating conditions, and stable hemodynamics. Short-acting and easily titratable analgesics are excellent choices for this maneuver. In this study, our aim was to determine an appropriate dosage regimen of remifentanil for awake nasotracheal fiberoptic intubation. For that reason, we compared two different dosage regimens. Twenty-four patients were randomly assigned to receive remifentanil 0.75 &mgr;g/kg in bolus, followed by a continuous infusion of 0.075 &mgr;g · kg−1 · min−1 (Group L), or remifentanil 1.5 &mgr;g/kg in bolus, followed by a continuous infusion of 0.15 &mgr;g · kg−1 · min−1 (Group H). All patients were premedicated with midazolam 0.05 mg/kg IV and glycopyrrolate 0.2 mg IV. Both dosage regimens ensured patient comfort and sedation. Discomfort did not differ between groups. Patients in Group H were sedated more profoundly. Hemodynamic stability was maintained with both remifentanil doses. Intubating conditions were adequate in all patients and comparable between the groups. The large dosage regimen did not result in any additional benefit compared with the small dosage. For awake nasotracheal fiberoptic intubation, we therefore recommend remifentanil 0.75 &mgr;g/kg in bolus followed by continuous infusion of 0.075 &mgr;g · kg−1 · min−1, supplemented with midazolam 0.05 mg/kg.

Which of the Abbreviated Burn Severity Index Variables Are Having Impact on the Hospital Length of Stay

Quality control is an important tool ensuring continuous medical efficacy. Outcome scores, however, are unfavorable from a statistical point of view, are not meaningful for less severely injured patients, and may put the treating physicians under pressure to limit therapeutic efforts. In this study the variables of the abbreviated burn severity index (ABSI), primarily an outcome score, were used to predict length of hospital stay (HLS), a continuous quantitative variable reflecting treatment costs and incidence of complications even in less severely injured patients. For 365 patients a multiple linear regression analysis was used to evaluate the influence of the ABSI variables on HLS. Among survivors, age and total body surface area burned (TBSA) contributed significantly to HLS, whereas for nonsurvivors only TBSA significantly influenced HLS. Neither gender nor presence of full-thickness burn or inhalation injury showed a significant influence on HLS. The impact of age and TBSA on HLS might be used as a benchmarking system to evaluate quality of care. However, although HLS is probably widely dependent on regional health care systems, TBSA and age proved to be the only variables of the ABSI to correlate with HLS.

Propofol without muscle relaxants for conventional or fiberoptic nasotracheal intubation: a dose-finding study.

UNLABELLED Endotracheal intubation has been performed during the administration of propofol anesthesia without neuromuscular blockade. In this study, we determined the propofol dose required for conventional nasotracheal or for fiberoptic nasotracheal intubation of all patients. Thirty-two patients undergoing maxillofacial surgery were randomly assigned to the conventional (n = 16) or to the fiberoptic (n = 16) intubation group. In both groups, anesthesia was induced by using IV fentanyl and IV titrated propofol according to clinical need (spontaneous respiration rate, verbal response). An endotracheal tube was placed nasally in the pharynx and the vocal cords visualized by using a fiberscope inserted via the tube. In the conventional group, the larynx was visualized additionally with a laryngoscope blade (Miller). In both groups propofol was titrated until the vocal cords opened. Patients were tracheally intubated, and the propofol dose was recorded. In all patients, the trachea could be intubated without the use of muscle relaxants. Considerable interindividual differences of dose requirements were observed. The amount of propofol required in the conventional group was significantly (P < 0.0001) larger (median +/- SD: 2.74 +/- 1.59 mg/kg; range 1.95-7.07 mg/kg) than in the fiberoptic group (1.37 +/- 0.59 mg/kg; 0.72-2.86 mg/kg). Hemodynamics remained stable in all patients. Postintubational hoarseness occurred in three patients of each group. Fiberoptic nasal intubation without a muscle relaxant can be facilitated with significantly smaller and more predictable dosages of propofol than conventional nasal endotracheal intubation. The possibility of titrating the propofol dose under assisted ventilation until the vocal cords open during fiberoptic nasotracheal intubation and the better predictability of the required dose favors the fiberoptic approach. IMPLICATIONS In this study, contrary to all preceding studies using predefined doses of propofol and opioids, we determined the minimal required propofol dose in combination with fentanyl for conventional or fiberoptic nasotracheal intubation without muscle relaxants.

Impact of early high caloric duodenal feeding on the oxygen balance of the splanchnic region after severe burn injury

Early enteral nutrition is recommended in burned patients. Depending on the amount administered, enteral feeding causes an increase of intestinal oxygen-demand. Although early moderate enteral nutrition has been shown to be beneficial, early high calorie enteral nutrition might lead to an imbalance of the O(2)-balance of the gut since intestinal perfusion is decreased after major burns. In 20 severely burned patients during the first 48 h of early high caloric duodenal feeding an assessment of the CO(2)-gap between the arterial and the gastric CO(2), as parameter for the intestinal O(2)-balance, was performed. Time points were prior to starting the enteral nutrition (BASE) subsequently every 30 min after increasing the amount of nutrition administered and from the 11th to the 48th h after beginning of nutrition in intervals of 6 h. In none of the patients was the CO(2)-gap increased during the rapid increase of enteral nutrition. On the contrary the CO(2)-gap decreased significantly. We conclude that high caloric duodenal feeding in the early hypodynamic postburn phase does not have adverse effects on the oxygen balance of the intestine.

The axillary vein central venous catheter in severely burned patients

In severely burned patients the approach to the central vein is often difficult due to concomitant edema, but also due to the fact that the skin area, where commonly used approaches are performed, is burned as well, whereas the axillary region is often not involved. In order to perform an axillary approach to the central vein as an alternative to the commonly used approaches in patients, an anatomical dissection in fresh human cadavers was carried out. Considering the anatomical landmarks which were found during dissection of the axillary region, the axillary approach to the central vein was used in 35 patients in our intensive burn care unit with unaffected axillary skin. In three cases the only complication observed was an occasional puncture of the axillary artery without major hematoma. The infection rate of the catheters was similar to the commonly used puncture sites. This approach to the central venous line in severely burned patients can be recommended.

The influence of deliberate hypotension on splanchnic perfusion balance with use of either isoflurane or esmolol and nitroglycerin.

Various techniques to induce deliberate hypotension (DH) have different influences on splanchnic perfusion. The aim of our study was to determine whether splanchnic perfusion is clinically impaired during DH by using either isoflurane (ISO) or a combination of esmolol and nitroglycerin (E/N). We randomized 16 patients undergoing elective maxillofacial surgery to receive either ISO (0.7%–1.8%) or E (105 g · kg−1 · min−1) and N (1–6 mg/h) to induce DH. General anesthesia was performed in both groups by IV midazolam 0.07 mg/kg, fentanyl 0.003 mg/kg, propofol 1.5 mg/kg, and vecuronium 0.1 mg/kg followed by a propofol infusion with 6 mg · kg−1 · h−1. After the induction of anesthesia, a gastric tonometer (TRIP®NGS Catheter) and a radial artery catheter were inserted. Baseline values of gastric intramucosal pH (pHi) were determined 60 min after placement of the catheter and before the induction of DH. The pHi values were calculated every 60 min until DH was discontinued. In both groups, DH was satisfactorily established. None of the pHi values calculated was less than 7.37 in the E/N or 7.41 in the ISO group. Arterial blood lactate levels did not increase in any of the patients. We conclude that neither method of producing DH compromises splanchnic tissue oxygen balance in healthy patients. Furthermore, overall organ perfusion was sufficient in both groups, because none of the patients showed an increase in blood lactate.

Impact of duodenal feeding on the oxygen balance of the splanchnic region during different phases of severe burn injury

Enteral nutrition is recommended in burned patients. Depending on the amount administered, enteral feeding causes an increase of intestinal oxygen-demand. Since intestinal perfusion is decreased after major burns the aim of this study was to evaluate, whether duodenal feeding might be a cofactor for the development of a splanchnic O(2)-imbalance. In 15 severely burned patients during duodenal feeding starting within 6 h after injury the assessment of the CO(2)-gap between arterial and gastric CO(2), as a parameter for the measurement of intestinal O(2)-balance was performed. Beginning prior to enteral nutrition CO(2)-gap measurements were carried out to show when the CO(2)-gap increased above 30 mmHg during the whole critical illness phase of the patients. When the CO(2)-gap increased above 30 mmHg enteral nutrition was reduced by 50% and the CO(2)-gap was measured 1 h later. In none of the patients the CO(2)-gap increased during increase of enteral nutrition. In seven patients, the CO(2)-gap increased between the 6th and 13th day above 30 mmHg and fell significantly 1 h after reduction of enteral nutrition. Contrary to the early postburn phase, enteral feeding might have adverse effects on the oxygen balance of the intestine in the later stages of the critical illness phase.